Problem: You are given an unweighted tree with n vertices. Recall that a tree is a connected undirected graph without cycles.

Your task is to choose three distinct vertices a, b, c on this tree such that the number of edges which belong to at least one of the simple paths between a and b, b and c, or a and c is the maximum possible. See the notes section for a better understanding.

The simple path is the path that visits each vertex at most once.

Input

The first line contains one integer number n (3 ≤ n ≤ 2 ⋅ 10^5) — the number of vertices in the tree. 

Next n - 1 lines describe the edges of the tree in form a_i, b_i (1 ≤ a_i, b_i ≤ n, a_i ≠ b_i). It is guaranteed that given graph is a tree.

Output

In the first line print one integer res — the maximum number of edges which belong to at least one of the simple paths between a and b, b and c, or a and c.

In the second line print three integers a, b, c such that 1 ≤ a, b, c ≤ n and a ≠, b ≠ c, a ≠ c.

If there are several answers, you can print any.

Example

Input


8
1 2
2 3
3 4
4 5
4 6
3 7
3 8


Output


5
1 8 6

Note

The picture corresponding to the first example (and another one correct answer):

<image>

If you choose vertices 1, 5, 6 then the path between 1 and 5 consists of edges (1, 2), (2, 3), (3, 4), (4, 5), the path between 1 and 6 consists of edges (1, 2), (2, 3), (3, 4), (4, 6) and the path between 5 and 6 consists of edges (4, 5), (4, 6). The union of these paths is (1, 2), (2, 3), (3, 4), (4, 5), (4, 6) so the answer is 5. It can be shown that there is no better answer.

Solution (in JAVA):

Solution:
import java.io.*; 
import java.util.*; 
//import javafx.util.*; 
import java.math.*;
//import java.lang.*;
public class Main 
{ 
    
    static int n;
    static ArrayList<Integer> adj[];
    
     static boolean vis[];
   //  static long ans[];
    static int arr[];
    static long mod=1000000007;
    static final long oo=(long)1e18;
    // static int n;
    public static void main(String[] args) throws IOException { 
    //    Scanner sc=new Scanner(System.in);
        PrintWriter pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
        br = new BufferedReader(new InputStreamReader(System.in));
       // int test=nextInt();
        int test=1;
        outer: while(test--!=0){ 
            n=nextInt();
            adj=new ArrayList[n];
            vis=new boolean[n];
            for(int i=0;i<n;i++)
                adj[i]=new ArrayList<Integer>();
            for(int i=0;i<n-1;i++){
                int a=nextInt();
                int b=nextInt();
                adj[a-1].add(b-1);
                adj[b-1].add(a-1);
            }
            ArrayList<Integer> temp=dfs(0);
            Arrays.fill(vis,false);
            ArrayList<Integer> ans=dfs(temp.get(0));
          //  System.out.println(ans);
            Queue<Integer> q=new LinkedList<Integer>();
            int d[]=new int[n];
            Arrays.fill(d,-1);
            for(int a:ans){
                q.add(a);
                d[a]=0;
            }
            while(!q.isEmpty()){
                int u=q.remove();
                for(int v:adj[u]){
                    if(d[v]==-1){
                        d[v]=d[u]+1;
                        q.add(v);
                    }
                }
            }
            int max_v=ans.get(1);
            int max=0;
            for(int i=0;i<n;i++){
                if(d[i]>max){
                    max=d[i];
                    max_v=i;
                }
            }
            pw.println(ans.size()-1+max);
            pw.println((ans.get(0)+1)+" "+(ans.get(ans.size()-1)+1)+" "+(max_v+1));
        }   
        pw.close();
    }
    static ArrayList<Integer> dfs(int v){
        vis[v]=true;
        int max=0;
        ArrayList<Integer> arr=null;
        for(int a:adj[v]){
            if(!vis[a]){
                ArrayList<Integer> b=dfs(a);
                if(b.size()>max){
                    max=b.size();
                    arr=b;
                }
            }
        }
        if(arr==null){
            arr=new ArrayList<Integer>();
        }
        arr.add(v);
        return arr;
    }

    static long ncr(long n,long r){
        if(r==0)
            return 1;
        long val=ncr(n-1,r-1);
        val=(n*val)%mod;
        val=(val*modInverse(r,mod))%mod;
        return val;
    }

    static int find(ArrayList<Integer> a,int i){
        
        if(a.size()==0||i<0)return 0;
        ArrayList<Integer> l=new ArrayList<Integer>();
        ArrayList<Integer> r=new ArrayList<Integer>();
        for(int v:a){
            if((v&(1<<i))!=0)l.add(v);
            else r.add(v);
        }

        if(l.size()==0)return find(r,i-1);
        if(r.size()==0)return find(l,i-1);
        return Math.min(find(l,i-1),find(r,i-1))+(1<<i);
    }
    
    
    public static BufferedReader br;
    public static StringTokenizer st;
    public static String next() {
        while (st == null || !st.hasMoreTokens()) {
       try {
                st = new StringTokenizer(br.readLine());
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
        return st.nextToken();
    }
 
    public static Integer nextInt() {
        return Integer.parseInt(next());
    }
    public static Long nextLong() {
        return Long.parseLong(next());
    }
 
    public static Double nextDouble() {
        return Double.parseDouble(next());
    }
    // static class Pair{
    //     int x;int y;
    //     Pair(int x,int y,int z){
    //         this.x=x;
    //         this.y=y;
    //        // this.z=z;
    //      //   this.z=z;
    //       //  this.i=i;
    //     }
    // }
    // static class sorting implements Comparator<Pair>{
    //     public int compare(Pair a,Pair b){
    //         //return (a.y)-(b.y);
    //         if(a.y==b.y){
    //             return -1*(a.z-b.z);
    //         }
    //         return (a.y-b.y);
    //     }
   // }
    public static int[] na(int n)throws IOException{
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = nextInt();
        return a;
    }
    static class query implements Comparable<query>{
        int l,r,idx,block;
        static int len;
        query(int l,int r,int i){
            this.l=l;
            this.r=r;
            this.idx=i;
            this.block=l/len;
        }   
        public int compareTo(query a){
            return block==a.block?r-a.r:block-a.block;
        }
    }
    static class Pair implements Comparable<Pair>{
        int x;int y;
        Pair(int x,int y){
            this.x=x;
            this.y=y;
            //this.z=z;
        }   
        public int compareTo(Pair p){
            
            return (x-p.x);
            //return (x-a.x)>0?1:-1;
        }
    }
    // static class sorting implements Comparator<Pair>{  
    //     public int compare(Pair a1,Pair a2){  
    //         if(o1.a==o2.a)
    //             return (o1.b>o2.b)?1:-1;  
    //         else if(o1.a>o2.a)  
    //             return 1;  
    //         else  
    //             return -1;  
    //     }
    // }  
    static boolean isPrime(int n) { 
        if (n <= 1) 
            return false; 
        if (n <= 3) 
            return true; 
        if (n % 2 == 0 ||  
            n % 3 == 0) 
            return false; 
      
        for (int i = 5; 
                 i * i <= n; i = i + 6) 
            if (n % i == 0 || 
                n % (i + 2) == 0) 
                return false; 
      
        return true; 
    } 
    static long gcd(long a, long b) { 
      if (b == 0) 
        return a; 
      return gcd(b, a % b);  
    }  
    // To compute x^y under modulo m 
    static long power(long x, long y, long m){ 
        if (y == 0) 
            return 1;      
        long p = power(x, y / 2, m) % m; 
        p = (p * p) % m; 
      
        if (y % 2 == 0) 
            return p; 
        else
            return (x * p) % m; 
    }
    static long fast_pow(long base,long n,long M){
        if(n==0)
           return 1;
        if(n==1)
        return base;
        long halfn=fast_pow(base,n/2,M);
        if(n%2==0)
            return ( halfn * halfn ) % M;
        else
            return ( ( ( halfn * halfn ) % M ) * base ) % M;
    }
       static long modInverse(long n,long M){
        return fast_pow(n,M-2,M);
    }
    
}